What do you mean by free electrons? Distinguish conductor and insulator in this regard
Electrons are normally bound to atoms. This is because they carry a negative charge and atoms have a nucleus composed of positively charged particles. It is understood that electrons occupy 'energy levels' near the nucleus. In some sense, they sorta 'stick around' the atom being attracted to its nucleus. In some materials, outermost electrons are quite loosely bound to the atoms and it takes very little energy to kick them off to move around freely (across atoms).
These are known as the 'free electrons'. When an external voltage is applied, they get kicked off from their atoms and are bound to them no more. They start moving around influenced by the potential difference. This flow is what 'electric current' really is. - The conductors are having the free electrons which are the reason behind their ability to be the conductor. While the insulators are not having the free electrons so they are not having this ability as well.
Comparison Chart Basis For Comparison Conductor Insulator Definition Material which permits the electric current or heat to pass through it. Restrict the electric current or heat to pass through it. Electric Field Exist on the surface but remain zero inside the conductor. Do not exist on insulator. Magnetic Field Store energy Do not store energy Potential Remain same at all the point on conductor. Remain zero. Thermal Conductivity High Low Covalent bond Weak Strong Conductivity Very high Low Resistance Low High Electrons Freely move Do not move freely Resistivity Vary from high to low High Temperature coefficient Positive temperature coefficient of resistance Negative temperature coefficient of resistance Conduction band Full of electrons Remain empty Valence Band Remains Empty Full of electrons Forbidden gap No forbidden gap Large forbidden gap Examples Irons, aluminum, silver, copper, etc. Rubber, wood, Paper, etc. Application For making electrical wires and conductor As a insulation in electrical cables or conductor, for supporting electrical equipment etc.
Definition of Conductor The conductor is defined as the material which allows the electric current or heat to pass through it. The electrons in a conductor freely moved from atom to atom when the potential difference is applied across them. The conductivity of the conductor depends on the number of free electrons in the outermost shell of the orbit. The conductivity of the material is directly proportional to the number of free electrons.
The conductivity of the material is directly proportional to the number of free electrons.The valence band and conductance band of a conductor are overlapped each other and hence there is no forbidden energy gap. The resistance of the conductor is very low due to which the charges freely move from place to place when the voltage is applied across them. Copper, aluminium, silver, mercury, etc. are some of the examples of the conductor.
Definition of Insulator The materials which do not allow the electric current or heat to pass through it such type of material is called an insulator. The covalent bond between the atoms of an insulator is very strong.Thus, the electrons or charges do not move freely. The resistivity of the insulator is very high.
The forbidden gap between the valence band and conduction band of an insulator is very large, and hence the electrons require large energy for moving from valence band to conduction band.
The insulator is mainly used for separating the conductor and for supporting the electrical equipment. It is also used in an electrical cable. Paper, wood, porcelain, etc., are some of the examples of an insulator.
Key Differences Between Conductor and Insulator - The conductor is the type of material which allows the electric current or heat to pass through it whereas the insulator does not allow the electric current or heat to pass through it.
- The electric field exists only on the surface of the conductor, and it remains zero inside the conductor whereas it does not exist on an insulator.
- The conductor, when placed in a magnetic field do not store energy whereas the insulator stored energy in a magnetic field.
- The thermal conductivity of the conductor is high, whereas the thermal conductivity of the insulator is low.
- Thermal conductivity is the property of the material which allows the heat to pass through it without any obstruction.
- The covalent bond between the atoms of a conductor is very weak whereas in an insulator it is very strong.
- The covalent bond is the chemical bond between the atoms which involve the sharing of electrons.
- In conductor, the electrons freely move from atom to atom whenever a potential difference is applied across it whereas, in an insulator, the electrons are fixed due to atomic level forces.
- The conductivity of the conductor is high, whereas the conductivity of the insulators is low.
- Conductivity is the rate at which the heat or charge flows through the material.
- The resistance of the conductor is very less, and hence the electrons freely move from atom to atom. The resistance of the insulator is very high.
- The conductor has a large number of free electrons whereas insulator does not have a large number of free electrons.
- The potential on the conductor remains same at all the point whereas in insulators the potential remains zero.
- The resistivity of the conductor varies from high to low whereas the resistivity of an insulator is very high.
- Resistivity is the resisting power of the material.
- The conductor has positive thermal coefficient of resistance whereas the insulator has the negative thermal coefficient of resistance..
- The thermal coefficient of resistance describes the change in the physical property of the material with temperature. If the resistance increases with the temperature, then it is called the positive thermal coefficient of resistance. In negative thermal coefficient, the resistance decreases with the increase in temperature.
- The conduction band of a conductor is full of electrons whereas the conduction band of an insulator is empty.
- The valence band of a conductor is empty whereas the valence band of an insulator is full of electrons.
- There is no forbidden gap in conductor whereas the forbidden gap in an insulator is very large.
- The forbidden gap is the gap between the valence band and the conduction band of material. It determines the conductivity of the material. If the gap is small, then the electron is easily moved from the valence band to the conduction band and hence the material is considered as a conductor. If the gap between them is large, then the material is express as an insulator.
- Copper, silver, aluminium, mercury are the examples of the conductor. The wood, paper, ceramic etc., are the examples of an insulator.
- The conductor is used for making electrical wires and cables.The insulator is used for separating the current carrying conductors and for supporting the electrical equipment.
These are known as the 'free electrons'. When an external voltage is applied, they get kicked off from their atoms and are bound to them no more. They start moving around influenced by the potential difference. This flow is what 'electric current' really is.
- The conductors are having the free electrons which are the reason behind their ability to be the conductor. While the insulators are not having the free electrons so they are not having this ability as well.
Comparison Chart Basis For Comparison Conductor Insulator
| Definition | Material which permits the electric current or heat to pass through it. | Restrict the electric current or heat to pass through it. |
| Electric Field | Exist on the surface but remain zero inside the conductor. | Do not exist on insulator. |
| Magnetic Field | Store energy | Do not store energy |
| Potential | Remain same at all the point on conductor. | Remain zero. |
| Thermal Conductivity | High | Low |
| Covalent bond | Weak | Strong |
| Conductivity | Very high | Low |
| Resistance | Low | High |
| Electrons | Freely move | Do not move freely |
| Resistivity | Vary from high to low | High |
| Temperature coefficient | Positive temperature coefficient of resistance | Negative temperature coefficient of resistance |
| Conduction band | Full of electrons | Remain empty |
| Valence Band | Remains Empty | Full of electrons |
| Forbidden gap | No forbidden gap | Large forbidden gap |
| Examples | Irons, aluminum, silver, copper, etc. | Rubber, wood, Paper, etc. |
| Application | For making electrical wires and conductor | As a insulation in electrical cables or conductor, for supporting electrical equipment etc. |
Definition of Conductor
The conductor is defined as the material which allows the electric current or heat to pass through it. The electrons in a conductor freely moved from atom to atom when the potential difference is applied across them. The conductivity of the conductor depends on the number of free electrons in the outermost shell of the orbit. The conductivity of the material is directly proportional to the number of free electrons.
The conductivity of the material is directly proportional to the number of free electrons.The valence band and conductance band of a conductor are overlapped each other and hence there is no forbidden energy gap. The resistance of the conductor is very low due to which the charges freely move from place to place when the voltage is applied across them. Copper, aluminium, silver, mercury, etc. are some of the examples of the conductor.
The materials which do not allow the electric current or heat to pass through it such type of material is called an insulator. The covalent bond between the atoms of an insulator is very strong.Thus, the electrons or charges do not move freely. The resistivity of the insulator is very high.
The forbidden gap between the valence band and conduction band of an insulator is very large, and hence the electrons require large energy for moving from valence band to conduction band.
The insulator is mainly used for separating the conductor and for supporting the electrical equipment. It is also used in an electrical cable. Paper, wood, porcelain, etc., are some of the examples of an insulator.
- The conductor is the type of material which allows the electric current or heat to pass through it whereas the insulator does not allow the electric current or heat to pass through it.
- The electric field exists only on the surface of the conductor, and it remains zero inside the conductor whereas it does not exist on an insulator.
- The conductor, when placed in a magnetic field do not store energy whereas the insulator stored energy in a magnetic field.
- The thermal conductivity of the conductor is high, whereas the thermal conductivity of the insulator is low.
- Thermal conductivity is the property of the material which allows the heat to pass through it without any obstruction.
- The covalent bond between the atoms of a conductor is very weak whereas in an insulator it is very strong.
- The covalent bond is the chemical bond between the atoms which involve the sharing of electrons.
- In conductor, the electrons freely move from atom to atom whenever a potential difference is applied across it whereas, in an insulator, the electrons are fixed due to atomic level forces.
- The conductivity of the conductor is high, whereas the conductivity of the insulators is low.
- Conductivity is the rate at which the heat or charge flows through the material.
- The resistance of the conductor is very less, and hence the electrons freely move from atom to atom. The resistance of the insulator is very high.
- The conductor has a large number of free electrons whereas insulator does not have a large number of free electrons.
- The potential on the conductor remains same at all the point whereas in insulators the potential remains zero.
- The resistivity of the conductor varies from high to low whereas the resistivity of an insulator is very high.
- Resistivity is the resisting power of the material.
- The conductor has positive thermal coefficient of resistance whereas the insulator has the negative thermal coefficient of resistance..
- The thermal coefficient of resistance describes the change in the physical property of the material with temperature. If the resistance increases with the temperature, then it is called the positive thermal coefficient of resistance. In negative thermal coefficient, the resistance decreases with the increase in temperature.
- The conduction band of a conductor is full of electrons whereas the conduction band of an insulator is empty.
- The valence band of a conductor is empty whereas the valence band of an insulator is full of electrons.
- There is no forbidden gap in conductor whereas the forbidden gap in an insulator is very large.
- The forbidden gap is the gap between the valence band and the conduction band of material. It determines the conductivity of the material. If the gap is small, then the electron is easily moved from the valence band to the conduction band and hence the material is considered as a conductor. If the gap between them is large, then the material is express as an insulator.
- Copper, silver, aluminium, mercury are the examples of the conductor. The wood, paper, ceramic etc., are the examples of an insulator.
- The conductor is used for making electrical wires and cables.The insulator is used for separating the current carrying conductors and for supporting the electrical equipment.
